gas-fired absorption development at ornl - aceee · gas-fired absorption heat pump water heater...

Gas-Fired

Absorption

Heat Pump

Water Heater

Development at

ORNL

Kyle Gluesenkamp Omar Abdelaziz Ed Vineyard

Building Equipment Research Oak Ridge National Laboratory

Sept. 4, 2013 ACEEE Hot Water Forum Atlanta, GA

2 / 15 GHPWH Development at ORNL

Overview

• Background

– Water heater primary energy consumption

– Market for gas heat pump water heaters

• Prototype development

• Working fluids

– Glycols

– Ionic liquids

• Simulation tools for absorption machines (ABSIM)


Project at ORNL

Project goals:

• Increase energy factor (EF) of gas storage water heating from ~0.65 to >1.0, with zero GWP and zero ODP

• Target retrofit market

• Identify and meet appropriate cost targets

Impact:

• Reduce 1.29 Quads/yr used in water heaters by >0.45 Quads with full adoption


Project at ORNL

Partners and Collaborators:

CRADA partner is GE. Other collaborators are:• Yankee Scientific, Inc. – breadboard prototype• Ionic Research Technologies, LLC – ionic liquids• Purdue University – update of ABSIM• University of Florida – membrane systems• Sentech/SRA International, Inc. – market assessment

Technology Transfer:• Target is a commercialized residential unit with EF>1.0 at

<$300 price premium over standard gas technology


Primary Energy Ratio of Water Heaters

• HPWHs can leapfrog condensing gas WHs

• Cost and novelty are current barriers – R&D needed

𝑃𝐸𝑅 = 𝐸𝐹Gas HPWH

Hot

water

Losses

𝑷𝑬𝑹 ≈ 𝟏. 𝟎 +

Ambient

heat

Fuel

𝑃𝐸𝑅 = 𝐸𝐹Gas WH Hot water

Losses

𝑷𝑬𝑹 ≈ 𝟎. 𝟔𝟓Fuel

Non-condensing gas burner WH

Non-condensing gas HPWH


Primary Energy Ratio of Water Heaters

• PER potential of gas HPWH greater than electric HPWH

• Cost and novelty are current barriers – R&D needed

𝑃𝐸𝑅 = 𝜂𝑔𝑟𝑖𝑑𝐸𝐹

Fuel Hot water

Losses

𝑃𝐸𝑅 ≈ 0.33 ∗ 2.5

𝑷𝑬𝑹 ≈ 𝟎. 𝟖𝟑

𝑃𝐸𝑅 = 𝜂𝑔𝑟𝑖𝑑𝐸𝐹Fuel

Electricity Hot water

Losses 𝑃𝐸𝑅 ≈ 0.33 ∗ 0.9

𝑷𝑬𝑹 ≈ 𝟎. 𝟑𝟎

𝑃𝐸𝑅 = 𝐸𝐹

Power plantElectric

HPWH

Power plant

Elec WH

Gas HPWH𝑷𝑬𝑹 ≈ 𝟏. 𝟎 +

Ambient

heat

Ambient

heat

Fuel

Electricity

Losses

Losses

Hot

water

Losses


HVAC Burden: Gas vs. Electric HPWH

Thermally

driven

heat pump

Nat. gas

0.9 unit

Evaporator:

heat from

conditioned

space

Electricity

COPth ≈ 1.5

EF ≈ 1.2 (example only)

COPelec ≈ 3

EF ≈ 2.5

Hot

water

0.8 unit

0.2 unit

Evaporator:

heat from

conditioned

space

0.4 unit

0.6 unit

0.9 unit Hot

water

Mechanic-

ally driven

heat pump

• Space cooling effect is ~3-5x lower for gas HPWHs compared to electric HPWHs (also less CFM required)

• Enhanced suitability for conditioned spaces in cold climates

𝑄𝑒𝑣𝑎𝑝𝑄𝐻𝑊

= 1 −1

𝐸𝐹

Losses to

conditioned space

0.1 unit 0.1 unit Losses to

conditioned space

(ignores flue losses for gas)


Market for Gas-fired HPWHs

Water heater install location

Retrofit payback period favorable with ~$300 price premium

(compared with standard efficiency gas storage)


Prototype DevelopmentTe

mpe

ratu

re

Abs

orpt

ion

heat

pum

p

Heat from

combustion

Hot waterHeat from

ambient

Heat to water from fuel

and ambient


Working Fluids – Crystallization

Crystallization of salt solution at high temperature lift

Characterization of water/LiBr with 1,3 Propylene glycol anti-crystallization additive in progress at ORNL


Working Fluids – Ionic Liquids

Ionic liquid: an organic salt,

liquid at room temperature.

Common cations

Common anions

• Represent unique opportunity to advance

absorption technology

– Safe, environmentally benign

– Less corrosive than typical fluids

– No crystallization risk

• 1010 possible combinations of cations and

anions

– 103 described in literature

– 102 commercially available

– Need to explore options through modeling


Working Fluids – Ionic Liquids

Ionic liquid development is in progress. Physics-based modeling is coupled to process model and guided synthesis.

Guided synthesis

Computational

property

predictions

Precise lab

characterization

Process modeling / life cycle

analysis


ABSIM

• Application designed specifically for modeling absorption heat pump cycle performance

• Publically available, free tool

• Updating for modern computing environment

• Enhanced with advanced plotting functions and GUI

• Currently in beta phase

• Old version available upon request


References

• Abdelaziz, O., Vineyard, E., Zaltash, A. (2010). US Patent application 12/829,940, filed July 2, 2010. “Absorption heat pump system and method of using the same.” UT-Battelle ID 201002389.

• Abdelaziz, O., Maginn, E., Morrison, D. (2013). “Ionic fluid design for absorption heat pump applications.” Seminar 58 of 2013 Winter ASHRAE Conference, Dallas, TX, USA.

• Sikes, K., Blackburn, J., Abdelaziz, O. (2012). “Market assessment for high-performance gas absorption water heaters.” November 2012.

• Wang, K., Abdelaziz, O., Kisari, P., Vineyard, E. (2011). “State-of-the-art review on crystallization control technologies for water/LiBr absorption heat pumps.” International Journal of Refrigeration, vol. 34, pp. 1325-1337.

• Wang, Kai, Omar Abdelaziz, and Edward A. Vineyard. "The impact of water flow configuration on crystallisation in LiBr/H 2 O absorption water heater." International Journal of Energy Technology and Policy 7.4 (2011): 393-404.

• Brownell, D., Stevenson, A., Guyer, E. (2011). “Absorption heat pump water heater prototype, design report B.” Submitted by Yankee Scientific, Inc., under subcontract number 4000101964, May 24, 2011.

• Kisari, P., Wang, K., Abdelaziz, O., Vineyard, E. (2010). “Crystallization temperature of aqueous LiBr solutions at low evaporation temperature.” Road to Climate Friendly Chillers, Cairo, Egypt.

• Wang, K., Kisari, P., Abdelaziz, O., Vineyard, E. (2010). “Testing of crystallization temperature of a new working fluid for absorption heat pump systems.” Road to Climate Friendly Chillers, Cairo, Egypt.

Patent Applications:

Publications:


Acknowledgments

DOE Building Technologies Program, Emerging Technologies

gas-fired absorption development at ornl - aceee · gas-fired absorption heat pump water heater...

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